Transistors are core devices of integrated circuits. The formation of transistors typically involves implanting impurities into semiconductor substrates to form source and drain regions and lightly doped source and drain (LDD) regions. The implanted source and drain regions and LDD regions are then annealed, so that the implanted impurities are activated, and the defects caused by the implantation are reduced.
It was observed that twin boundary defects are often generated in the implanted LDD regions and source and drain regions. The twin boundary defects cause an increase in the leakage currents. Further, in the case the transistors are FinFETs, the twin boundary defects may be propagated to the subsequently formed epitaxy regions.